What the label lists and what reports show
Mefloquine side effects
Mefloquine's FDA label lists its adverse reactions in its own words. FAERS holds 156 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is anxiety (37 reports).
- Generic listed
- Boxed warning
Check it at the source: the mefloquine FDA label on DailyMed (effective November 18, 2024, Chartwell RX, LLC); the FDA FAERS public dashboard.
What does the patient leaflet say about side effects?
From the patient leaflet: What are the possible side effects of mefloquine?See “What is the most important information I should know about mefloquine?” Mefloquine may cause serious side effects, including: liver problems Call your healthcare provider right away if you have unexplained symptoms such as nausea or vomiting, stomach pain, fever, weakness, itching, unusual tiredness, loss of appetite, light colored bowel movements, dark colored urine, yellowing of your skin or the white of your eyes. The most common side effects of mefloquine include: nausea vomiting diarrhea abdominal pain headache The most common side effects in people who take mefloquine for treatment include: muscle pain fever chills skin rash fatigue loss of appetite irregular heart beat Tell your doctor if you have any side effect that bothers you or that does not go away. These are not all the possible side effects of mefloquine. For more information, ask your doctor or pharmacist. […]
Source: FDA drug label, Chartwell RX, LLC, effective November 18, 2024 (SPL set b884d22b-aae7-4f14-9a04-ae4029a229f0), via openFDA; the full label on DailyMed
What do FAERS reports show?
156 reports list mefloquine among the medicines taken, each a report of something that happened, not proof the medicine caused it; 14 are coded as a death and 53 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Of the 25 reactions below, 11 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.
The 25 most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Mefloquine: the full record
- label, generics, price, shortages, recalls
- Report a side effect to the FDA
- MedWatch
- Side effects hub
- the most reported medicines and reactions